The present invention concerns a method for applying flat material web sections onto a first flat material web moving in a machine direction at a first web speed during the production of hygiene articles or medical articles, wherein the extent of the flat material web sections in the machine direction is smaller than the dimension of the articles to be produced, wherein the flat material web sections are separated from an endless web using a “cut-and-place” procedure and are disposed onto the first flat material web, wherein the endless web is supplied towards a cutting roller of a cutting station at a second web speed. The first flat material web may also be a series of discrete articles. The invention also concerns a device for performing such a method, comprising a cutting roller and an anvil roller cooperating therewith.
The flat material web sections to be applied may e.g. be closing straps in the form of adhesive tape sections or sections comprising mechanical closing elements, or wound supports or gripping elements of bandaging materials, in particular adhesive bandages.
The articles to be produced, e.g. hygiene articles, such as diapers or diaper pants, are separated in sections from the preferably endless first flat material web moving in the machine direction. In order to produce these articles in an economic fashion, the flat material web sections to be applied are also separated from an endless web using the “cut-and-place” procedure and are disposed on the first flat material web, moving in the machine direction. Since the longitudinal extension of the flat material web sections to be applied is much smaller than the longitudinal extension of the article being produced, the first web speed of the first flat material web is faster than the second web speed with which the endless web is supplied to form the flat material web sections.
The following detailed problems arise:
When the endless web, which is supplied at a lower speed, is susceptible to slippage on an anvil roller, the endless web is subjected to abrasive wear. The peripheral speed of the anvil roller is many times higher, often up to 30 times higher, than the speed of the endless web in this contact area. Abrasion of the endless web soils the production device, and also transfers dirt particles onto the articles to be produced.
In particular, when adhesive coatings are used in the endless web, parts of the adhesive formed or sheared off during cutting, deposit on the anvil roller and are distributed about the overall periphery of the anvil roller due to the slippage of the endless web. They are also transported to the article to be produced via the flat material web sections being separated.
When flat material web sections are cut off from the endless web at relatively low speeds, and are then accelerated to a higher speed to be applied onto the first flat material web, one faces the problem that inertial masses must be accelerated and decelerated with high frequency. When relatively bending-resistant materials are used to form the flat material web sections, in particular, materials which are folded several times of top of each other, the reduction of the roller diameters in order to reduce the moved masses is problematic, since in this case, the bending-resistant materials and flat material web sections separated therefrom can hardly be kept on the surface of the anvil roller or other transport rollers. This would cause economically unacceptable disturbance of the production process.
For this reason, it has not been possible to find a satisfactory solution for the above-mentioned problems up to now.
It is therefore the underlying purpose of the present invention to provide a method and a device for performing the method, which permit application of flat material web sections onto a first flat material web extending in a machine direction to ensure economic production with high processing stability and which are not impaired by any of the above-mentioned problems.